I have always had an aversion to spraying pesticides, herbicides, or anything ending with “-cides,” partly out of laziness, partly out of ignorance, but largely out of fear. There was also the example of my mother’s garden, flourishing and feeding us without chemical help.

When I planted the white Rosa Rugosa “Sir Thomas Lipton” in 1996 – gasp! – can this be right? – I hoped it would mitigate the boring two-story east wall of the house. I trained it, clipping and tying the long stems to a purchased iron trellis. I think it looks a bit silly now, out of scale and style with the rest of the place, but it seemed perfect then. I planted common Clematis “Jackmanii” with it to twine its way through the rose canes and mingle its purple flowers with the white roses. Mrs. Paepcke had a wonderful one that romped over a wall near a gate. Mine has not romped, it straggles. The rose has never fulfilled my optimistic anticipation either; it is neither vigorous nor floriferous and the buds attract aphids. The pair of plants rarely even blooms in sync, and I contemplate replacing them, but when I do get flowers, well! The late garden writer Henry Mitchell said the “Sir Thomas Lipton” flower looks like a white camellia with a superb fragrance. Not too many camellias hereabouts, but I’m sure you get the picture. About the clematis, he said, “No need to be heartsick” if you don’t have any of the rare and fancy kinds since “the garden effect of such old kinds as ‘Jackmanii’ is fine enough.” So I give them another reprieve.

After about 10 years of reprieves, when I saw dozens of rose buds covered with hundreds of translucent apple-green aphids, and a plastic spray bottle of soapy water on the bench nearby, what did I do? I sprayed every rosebud thoroughly. While I was at it, I went into the greenhouse and zapped the white flies disfiguring and discoloring the new leaves on my prize angel’s trumpet, Brugmansia “Charles Grimaldi.” They proliferate like crazy when it gets warm.

Usually I kill bugs in hand-to-hand combat, always pretty satisfying, if a bit primitive and yucky. Fingertips run over a bud or leaf surface easily smush fragile aphids and the ants that herd them for the honeydew that seeps out of their backs as they gorge plant juice. White flies are torpid and won’t disperse in a cloud in the cool of the day, and can be wiped off with the fingers too. I’ve been known to find the hose nozzle, drag out the hose and blast bugs away, a common tip for controlling bugs.

Several days after my spraying frenzy, all the leaves of the Brugmansia shriveled up and dropped off. Alarmed, I checked my rose. The buds were burnt and withered and so were the leaves around them. I felt like I sent my kids out to play with bare heads, arms and legs, and they got skin cancer from the sunburns.

I checked a bunch of reference books. Soap is soap, right? What do I know about soap ingredients? Maybe this was the wrong kind or too concentrated. I know that even plain water sprayed on leaves in the hot sun can burn them. According to High Country Roses, Rugosa roses in particular should never be sprayed as “their leaves are very sensitive and any type of chemical spray can cause them to defoliate.”

Insecticidal soap may be nontoxic, but it is still a chemical pesticide, and if it kills aphids or white flies, it also will kill beneficial insect predators like ladybugs or lacewings. There is a time lag. Since predator populations take longer to reproduce than their prey, I created a recipe for an explosion of aphids with no predators to balance them. So even if my spraying hadn’t been a lot more destructive to my plants than the bugs were, I have hurt the balance in my garden. I’ll let you know in a later column whether the rose and the angels trumpet have recovered from my foolishness, or if I have had to learn this lesson the hard way.

Anna is chagrined by how many mistakes she continues to make in the garden she tends with her husband Gerry in Basalt. Contact her via e-mail at either annasgarden@sopris.net or mail@aspentimes.com. Good information on insect and disease management can be had from Ecology Action in Willits, Calif., and “Practical Science for Gardeners” by Mary Pratt.

source : www.aspentimes.com